import  time
incomplete_sign = 50     # .的数量
print('='*23+'开始下载'+'='*25)
for i in range(incomplete_sign + 1):
    completed = "*"* i   #表示已完成
    incomplete = '.' * (incomplete_sign - i)   #表示未完成
    percentage = (i/incomplete_sign) * 100   #百分比
    print("\r{:.0f}%[{}{}]".format(percentage,completed,incomplete),end="")
    time.sleep(0.5)
    print("\n"+ '='*23+'下载完成'+'='*25)
